Bidirectional two-base bipolar junction transistor operation, circuits, and systems with double base short at initial turn-off

Abstract

Methods, systems, circuits, and devices for power-packet-switching power converters using bidirectional bipolar transistors (BTRANs) for switching. Four-terminal three-layer BTRANs provide substantially identical operation in either direction with forward voltages of less than a diode drop. BTRANs are fully symmetric merged double-base bidirectional bipolar opposite-faced devices which operate under conditions of high non-equilibrium carrier concentration, and which can have surprising synergies when used as bidirectional switches for power-packet-switching power converters. BTRANs are driven into a state of high carrier concentration, making the on-state voltage drop very low.

What is claimed is: 
     
       1. A method for switching a power bipolar semiconductor device which includes both an n-type emitter/collector region, and also a p-type base contact region, on each of both first and second opposing surfaces of a p-type semiconductor die, and which has an ON state and an OFF state, comprising the steps of:
 during the ON state, driving base current into one of the base contact regions; and 
 during transition to the OFF state,
 shorting the base contact region on the first surface to the emitter/collector region on the first surface, while also shorting the base contact region on the second surface to the emitter/collector region on the second surface, and 
 thereafter floating at least the base contact region on the first surface; 
 wherein the base contact region on the first surface is not connected to the base contact region on the second surface, except through the semiconductor die itself; 
 whereby externally-sourced current between the emitter/collector regions on the first and second opposing surfaces can thereby be controllably switched regardless of the direction of the current. 
 
 
     
     
       2. The method of  claim 1 , wherein the semiconductor die is silicon. 
     
     
       3. A method for switching a power bipolar semiconductor device which includes both a p-type emitter/collector region, and also an n-type base contact region, on each of both first and second opposing surfaces of an n-type semiconductor die, and which has an ON state and an OFF state, comprising the steps of:
 during the ON state, driving base current into one of the base contact regions; and 
 during transition to the OFF state,
 shorting the base contact region on the first surface to the emitter/collector region on the first surface, while also shorting the base contact region on the second surface to the emitter/collector region on the second surface, and 
 thereafter floating at least the base contact region on the first surface; 
 wherein the base contact region on the first surface is not connected to the base contact region on the second surface, except through the semiconductor die itself; 
 whereby externally-sourced current between the emitter/collector regions on the first and second opposing surfaces can thereby be controllably switched regardless of the direction of the current. 
 
 
     
     
       4. The method of  claim 3 , wherein the semiconductor die is silicon.